Shouldn't trimming the beard (i.e., cutting off hair with scissors, but not completely; e.g., to "shape" the beard) suffer from the same problem as cutting it off completely without using a razor, i.e., begged isha?

Rav Chaim Kanievsky, shlita, wrote the following in his sefer Orchos Yosher, section 5 (he does not mention the Tzemach Tzedek):

"Targum Yonoson states that one who commits this transgression violates the prohibition: “A man shall not wear woman’s dress.” This applies even if he trims his beard using scissors. Sefer HaChinuch also follows this view and adds that one [who does so] also violates the prohibition: “You shall not follow their statutes.” This is quoted by the Chofetz Chayim in his Sefer HaMitzvos HaKotzer (negative commandment 177)."

Rav Chaim Kanievsky, shlita, wrote the following in his sefer Orchos Yosher, section 5 (he does not mention the Tzemach Tzedek):

"Targum Yonoson states that one who commits this transgression violates the prohibition: “A man shall not wear woman’s dress.” This applies even if he trims his beard using scissors. Sefer HaChinuch also follows this view and adds that one [who does so] also violates the prohibition: “You shall not follow their statutes.” This is quoted by the Chofetz Chayim in his Sefer HaMitzvos HaKotzer (negative commandment 177)." קע"ז).